U.S. patent application number 17/120866 was filed with the patent office on 2022-06-16 for heating systems with unhoused centrifugal fan and wraparound heat exchanger.
The applicant listed for this patent is Rheem Manufacturing Company. Invention is credited to Robert L. Long.
Application Number | 20220186979 17/120866 |
Document ID | / |
Family ID | |
Filed Date | 2022-06-16 |
United States Patent
Application |
20220186979 |
Kind Code |
A1 |
Long; Robert L. |
June 16, 2022 |
HEATING SYSTEMS WITH UNHOUSED CENTRIFUGAL FAN AND WRAPAROUND HEAT
EXCHANGER
Abstract
A heating system with wraparound heat exchanger is disclosed.
The system includes a centrifugal fan that expels air radially into
a plenum space. A heat exchanger tube is placed in the plenum
space, thereby heating the air in the plenum space before it exits
an assembly cabinet. The heat exchanger tube can have various
configurations, including non-horizontal configurations so as to
allow condensate to drain from the heat exchanger tubes.
Inventors: |
Long; Robert L.; (Fort
Smith, AR) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Rheem Manufacturing Company |
Atlanta |
GA |
US |
|
|
Appl. No.: |
17/120866 |
Filed: |
December 14, 2020 |
International
Class: |
F24H 3/04 20060101
F24H003/04 |
Claims
1. A heat exchanger assembly comprising: a heat exchanger tube
comprising a first section, a second section, and a curved section
disposed between the first section and the second section; and a
centrifugal fan positioned between the first section and the second
section and configured to pull in air from a fan inlet and disperse
air across the first section, the second section, and the curved
section.
2. The heat exchanger assembly of claim 1, wherein the centrifugal
fan is a plenum fan and the heat exchanger tube is disposed within
a plenum space of the plenum fan.
3. The heat exchanger assembly of claim 2, wherein the plenum fan
is a direct drive single inlet unhoused plenum fan.
4. The heat exchanger assembly of claim 1, further comprising a
cabinet that contains the heat exchanger tube and the centrifugal
fan, the cabinet comprising at least one cabinet inlet positioned
proximate the fan inlet and one or more cabinet outlets.
5. The heat exchanger assembly of claim 1, wherein the first
section and the second section are parallel with respect to one
another.
6. The heat exchanger assembly of claim 5, wherein the first
section and the second section have a non-zero angle with respect
to horizontal when viewed from a side of the heat exchanger
tube.
7. The heat exchanger assembly of claim 1, wherein: the first
section has a first angle with respect to horizontal when viewed
from a side of the heat exchanger tube; and the second section has
a second angle with respect to horizontal when viewed from a side
of the heat exchanger tube, the second angle being a different
angle than the first angle.
8. The heat exchanger assembly of claim 7, wherein the first angle
is 0.degree..
9. The heat exchanger assembly of claim 7, wherein the second angle
is a decline angle, wherein a first position of the second section
proximate the curved section is higher with respect to horizontal
than a second portion of the second section proximate an ingress
portion of the heat exchanger tube.
10. The heat exchanger assembly of claim 1, wherein the first
section and the second section are substantially straight.
11. The heat exchanger assembly of claim 10, wherein a radius of
curvature of the curved section is less than 180.degree..
12. The heat exchanger assembly of claim 1, wherein a radius of
curvature of the curved section is less than 180.degree..
13. The heat exchanger assembly of claim 1, wherein a center of the
centrifugal fan is positioned at a first distance from the first
section and at a second distance from the second section, wherein
the first distance is a different distance than the second
distance.
14. A heating system comprising: a centrifugal fan comprising a fan
inlet; a heat exchanger tube positioned at least partially around
the centrifugal fan; and a cabinet that contains the centrifugal
fan and at least a portion of the heat exchanger tube, the cabinet
comprising an air inlet positioned proximate the fan inlet and an
air outlet, wherein the centrifugal fan is configured to disperse
air radially from a center of the centrifugal fan and across at
least a portion of the heat exchanger tube.
15. The heating system of claim 14, wherein the heat exchanger tube
comprises a first section, a second section, and a curved section
disposed between the first section and the second section.
16. The heating system of claim 15, wherein the first section and
the second section are parallel with respect to one another.
17. The heating system of claim 15, wherein the first section and
the second section have a non-zero angle with respect to horizontal
when viewed from a side of the heat exchanger tube.
18. The heating system of claim 15, wherein: the first section has
a first angle with respect to horizontal when viewed from a side of
the heat exchanger tube; and the second section has a second angle
with respect to horizontal when viewed from a side of the heat
exchanger tube, the second angle being a different angle than the
first angle.
19. The heating system of claim 18, wherein the second angle is a
decline angle, wherein a first position of the second section
proximate the curved section is higher with respect to horizontal
than a second portion of the second section proximate an ingress
portion of the heat exchanger tube.
20. The heating system of claim 14, wherein: the centrifugal fan is
a plenum fan; the cabinet defines a plenum space around the
centrifugal fan; and the heat exchanger tube is disposed within the
plenum space.
Description
FIELD OF THE DISCLOSURE
[0001] Examples of the present disclosure relate generally to
heating systems and, more specifically, to heating systems
including a centrifugal fan and a wraparound heat exchanger.
BACKGROUND
[0002] Conventional forced air heating systems include a fan unit
that forces air across one or more heating tubes of a heat
exchanger. The fan unit is typically positioned at a first location
within a system and the heating tubes are positioned at a second
location downstream from the fan. These systems have a number of
disadvantages that can lead to decreased efficiency. For one, the
fans used in most systems include a curved blower that has a single
air outlet that supplies the air flow across heating tubes. Because
this single air outlet supplies the air flow, the velocity of the
air exiting the blower must be substantially high so as to provide
sufficient flow across the downstream heating tubes, thereby
increasing the overall power consumption of the heating system.
Additionally, a conduit is provided between the curved blower and
the heating tubes to channel the air across the heating tubes. The
space required to provide this air channel can increase the
footprint of the overall heating unit.
[0003] Another disadvantage of prior systems includes the
non-uniform distribution of the air flow across the heating tubes.
For example, since the blower and the heating tubes are separated
from each other in prior designs, it is more difficult to channel
the air flow consistently across the entirety of the heating tubes.
This can lead to hot zones and cool zones across the heat
exchanger, decreasing the overall heating efficiency of the system.
What is needed, therefore, is an energy efficient system that
provides uniform air distribution around the heat exchanger to
increase the heating efficiently of the system.
BRIEF SUMMARY
[0004] These and other problems can be addressed by the
technologies described herein. Examples of the present disclosure
relate generally to heating systems and, more specifically, to
heating systems including a centrifugal fan and a wraparound heat
exchanger.
[0005] The present disclosure provides a heat exchanger assembly.
The heat exchanger assembly can include one or more heat exchanger
tubes and a centrifugal fan. The heat exchanger tube(s) can include
a first section, a second section, and a curved section between the
first section and the second section (i.e., the curved section can
fluidly connect the first section and the second section). The
centrifugal fan can be positioned between the first section and the
second section and can pull in air from a fan inlet and disperse
air across the first section, the second section, and the curved
section.
[0006] The centrifugal fan can be a plenum fan and the heat
exchanger tube(s) can be placed within a plenum space of the plenum
fan. The plenum fan can be a direct drive single inlet unhoused
plenum fan such that the heat exchanger tube(s) can be placed
adjacent the fan.
[0007] In some examples, the heat exchanger assembly can be housed
within an outer cabinet. The cabinet can include at least one
cabinet inlet positioned near the fan inlet, and the cabinet can
include one or more cabinet outlets.
[0008] The shapes and geometries of the heat exchanger tube, or the
sections of the heat exchanger tube, can be altered for various
design attributes. For example, the first section and the second
section can be parallel with respect to one another. The heat
exchanger tube(s) can also be positioned so as to reduce the
occurrence of condensation within the tube. The first section and
the second section can have a non-zero angle with respect to
horizontal when viewed from a side of the heat exchanger tube.
[0009] The first section can have a first angle with respect to
horizontal when viewed from a side of the heat exchanger tube, and
the second section can have a second angle with respect to
horizontal when viewed from a side of the heat exchanger tube. The
second angle can be a different angle than the first angle. The
first angle can be 0.degree.. The second angle can be a decline
angle, wherein a first position of the second section proximate the
curved section is higher with respect to horizontal than a second
portion of the second section proximate an ingress portion of the
heat exchanger tube.
[0010] The first section and the second section can be
substantially straight. A radius of curvature of the curved section
can be less than 180.degree., i.e., the heat exchanger tube(s) can
be wider at their ingress/egress portions that at the curved
section.
[0011] A center of the centrifugal fan can be positioned at a first
distance from the first section and at a second distance from the
second section, wherein the first distance is a different distance
than the second distance. By altering the positioning of the
centrifugal fan, the fan can be customized to avoid cool/hot spots
within the plenum space.
[0012] Another aspect of the present disclosure provides a heating
system. The heating system can include centrifugal fan including a
fan inlet. The heating system can include a heat exchanger tube
positioned at least partially around the centrifugal fan. The
heating system can include a cabinet that contains the centrifugal
fan and at least a portion of the heat exchanger tube. The cabinet
can include an air inlet positioned proximate the fan inlet and an
air outlet. The centrifugal fan can disperse air radially from a
center of the centrifugal fan and across at least a portion of the
heat exchanger tube.
[0013] The heat exchanger tube can include a first section, a
second section, and a curved section disposed between the first
section and the second section, as described above for the heat
exchanger assembly. The first section and the second section can be
parallel with respect to one another. The first section and the
second section can have a non-zero angle with respect to horizontal
when viewed from a side of the heat exchanger tube.
[0014] The first section can have a first angle with respect to
horizontal when viewed from a side of the heat exchanger tube, and
the second section can have a second angle with respect to
horizontal when viewed from a side of the heat exchanger tube, the
second angle being a different angle than the first angle. The
second angle can be a decline angle, wherein a first position of
the second section proximate the curved section is higher with
respect to horizontal than a second portion of the second section
proximate an ingress portion of the heat exchanger tube.
[0015] The centrifugal fan can be a plenum fan. The cabinet can
define a plenum space around the centrifugal fan, and the heat
exchanger tube can be positioned within the plenum space.
[0016] These and other aspects of the present disclosure are
described in the Detailed Description below and the accompanying
figures. Other aspects and features of the present disclosure will
become apparent to those of ordinary skill in the art upon
reviewing the following description of specific examples of the
present disclosure in concert with the figures. While features of
the present disclosure may be discussed relative to certain
examples and figures, all examples of the present disclosure can
include one or more of the features discussed herein. Further,
while one or more examples may be discussed as having certain
advantageous features, one or more of such features may also be
used with the various other examples of the disclosure discussed
herein. In similar fashion, while examples may be discussed below
as devices, systems, or methods, it is to be understood that such
examples can be implemented in various devices, systems, and
methods of the present disclosure.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] The accompanying drawings, which are incorporated in and
constitute a part of this specification, illustrate multiple
examples of the presently disclosed subject matter and serve to
explain the principles of the presently disclosed subject matter.
The drawings are not intended to limit the scope of the presently
disclosed subject matter in any manner. In the drawings:
[0018] FIG. 1 is a side view of a heat exchanger assembly within a
heating cabinet, according to the present disclosure;
[0019] FIG. 2 is a perspective view of a heat exchanger assembly
within an outer housing, according to the present disclosure;
[0020] FIG. 3 is a side view of a heat exchanger assembly within an
outer housing, according to the present disclosure;
[0021] FIG. 4 is a side perspective view of a heat exchanger
assembly within an outer housing, according to the present
disclosure; and
[0022] FIGS. 5A-5D are side schematic views of heat exchanger
assemblies, according to the present disclosure.
DETAILED DESCRIPTION
[0023] Forced air heating systems typically include a heating
element having one or more heating tubes and a fan to force air
across the heating element. In prior designs, these two devices
were separated a certain distance. A fan at one location in the
system provides air flow through ductwork or a cabinet such that
the air contacts the heat exchanger before exiting the system to
heat the building. Prior designs had a number of disadvantages that
increased the power consumption and decreased the heating
efficiency of the system. For one, separating the fan from the
heating element can decrease the efficiency of the system. A great
deal of air flow must be provided through the system to ensure
enough air comes in contact with the distally placed heat exchanger
tubes. Even with sufficient air flow, not all air flowing through
the system may interact evenly with the heating element, as certain
areas will have hot spots while other areas will have cool
spots.
[0024] Another inefficiency is found in the fan itself. Typical
existing systems utilize a curved blower that has a single air
outlet. The air exiting the blower must be at a high velocity so as
to provide sufficient flow across the downstream heating tubes,
thereby increasing the overall power consumption of the heating
system. More recently, manufacturers began incorporating plenum
fans in heating system designs. Plenum fans do not have a singular
outlet, but instead provide radial air flow to pressurize a space
around the fan. Because of this, the air flow provided by the fan
is slower, thereby lowering power consumption of the system.
However, prior plenum-system designs had a similar drawbacks when
it comes to heating efficiency. These systems also separate the fan
from the heating element. Since air must still flow through a
cabinet or ductwork to a downstream heating element, certain areas
will have hot spots while other areas will have cool spots, just as
in the blower system.
[0025] The present systems provide a solution to both the power and
the heating efficiency issues described above. The design includes
an unhoused centrifugal fan to pressurize a plenum space. Instead
of separating the heating element from the fan, like in prior
designs, the systems include one or more heating tubes placed
directly in the plenum space. A large radius bend in the heating
tube(s) can enable even air flow and decrease the occurrence of hot
spots in the air flow. After the air is evenly heated in the plenum
space, the heated air can exit the system at an outlet and travel
to heat the building. Various heating systems including a
centrifugal fan and a wraparound heat exchanger are disclosed, and
example systems will now be described with reference to the
accompanying figures.
[0026] FIG. 1 is a side view of a heat exchanger assembly 100. A
heat exchanger assembly 100 can include one or more heat exchanger
tubes 102. When reference is made herein to a singular heat
exchanger tube, it will be understood that the reference can refer
to a plurality of heat exchanger tubes. The heat exchanger tube 102
can include a first section 104, a second section 106, and a curved
section 108 located between the first section 104 and the second
section 106. The first section 104 and second section 106 can be
straight sections of the heat exchanger tube 102. However, as will
be described in greater detail below with reference to FIGS. 5A-5D,
other shapes and configurations for the heat exchanger tube 102 are
contemplated.
[0027] While the heat exchanger assembly 100 is described herein as
passing heated combustion gases through the heat exchanger tube
102, it is contemplated that the heat exchanger tube 102 can be
configured to pass refrigerant, water, or other fluids for
exchanging heat to another fluid passing over the exterior of the
heat exchanger tube 102. Further, while the heat exchanger assembly
100 is primarily described herein as providing heat (i.e.,
performing the functionality of a condenser), it is contemplated
that the heat exchanger assembly 100 can provide a cooling effect
(i.e., performing the functionality of an evaporator). Further
still, at certain points within this disclosure, the heat exchanger
assembly 100 is described as being included in a combined HVAC unit
(e.g., HVAC unit 75) including both heating and air-conditioning
elements. It is contemplated, however, that the heat exchanger
assembly 100 can be a standalone heat exchanger. For example, the
heat exchanger assembly 100 can be a standalone evaporator and/or a
standalone condenser.
[0028] The heat exchanger tube 102 can be placed around or at least
partially around a centrifugal fan 110. The centrifugal fan 110 can
be a plenum fan, backward inclined plug fan, or other direct drive
or belt drive radial fan. One benefit of a centrifugal fan is that
it requires less air velocity and, therefore, draws less power than
a blower to provide air flow. Air drawn into the centrifugal fan
can be expelled radially into a plenum space 502 within a heating
cabinet 200, thereby pressurizing the plenum space 502. Because the
centrifugal fan 110 can be unhoused, the heat exchanger tube 102
can be placed in the plenum space 502 directly adjacent the fan so
that the pressurized air can be evenly heated before the air exits
the heat exchanger assembly 100. In other words, the plenum space
502 can be defined as the space between the centrifugal fan 110 and
the heating cabinet 200 housing the centrifugal fan 110 and the
heat exchanger tube 102, and the tube can be placed within that
space.
[0029] At one end of the heat exchanger tube 102 can be an ingress
portion 112 of the tube. The ingress portion 112 can be positioned
proximate a burner assembly 150, for example a gas burner that
provides heated combustion gases to be passed through the heat
exchanger tube(s) 102. Heated air can enter the ingress portion 112
of the heat exchanger tube 102 and proceed to an egress portion 114
of the tube. The combustion gases can exit an outlet of each heat
exchanger tube 102 and flow through an opening near the egress
portion 114 of the tube. Although FIG. 1 depicts the ingress
portion 112, burner assembly 150, and second section 106 being
positioned at a bottom of the heat exchanger assembly 100, and the
egress portion 114 and first section 104 being positioned at a top,
this is merely illustrative, and the groups of features can be
repositioned such that either is on top or bottom of the heat
exchanger assembly 100. For example, the ingress portion 112 can be
positioned at the top in FIG. 1 and proximate a burner assembly 150
also positioned at the top.
[0030] The heat exchanger assembly 100 can be positioned within an
outer heating cabinet 200 that defines the plenum space 502. As
will be described herein, the heating cabinet 200 can include a
cabinet air outlet 206 and cabinet air inlet 204. When reference is
made herein to the heat exchanger assembly (e.g., heat exchanger
assembly 100), the term can be understood to include the heat
exchanger tube 102 and the centrifugal fan 110. When reference is
made herein to the "heating system" as a whole, the term heating
system can be understood to mean the heat exchanger assembly 100
packaged into a unit, for example via the heating cabinet 200. The
"heating system" will be referred to hereinafter as heating system
50. Further still, and as will be described below, the system as a
whole can include an outer housing 250 that can include the heating
system 50, an upstream section 302, and a lower section 306. Lower
section 306 can house a condensing unit, which can include a
condenser coil, outdoor fans, and refrigerant compressors (air for
the gas heat exchanger does not necessarily flow through lower
section 306 shown in FIG. 1).
[0031] FIG. 2 is a perspective view of a heat exchanger assembly
100. The centrifugal fan 110 can have a fan inlet 202 positioned to
draw air into the centrifugal fan 110. The fan inlet 202 can have a
conical shape with a circular opening along a plane. The fan inlet
202 can be positioned at the cabinet inlet 204 of the cabinet. The
heating cabinet 200 can include a plate (not shown in view) that
covers the cabinet inlet 204, and the plate can have a hole sized
to correspond to the fan inlet 202 so that the air is directed into
the centrifugal fan 110. The fan inlet 202 can be positioned at any
location within the heating cabinet 200 such that air can travel
into the inlet from an upstream duct system or cabinet. The heating
cabinet 200 can also include a cabinet outlet 206. The air leaving
the heating cabinet 200 at the cabinet outlet 206 can be heated
(e.g., by the heat exchanger tube 102), and ductwork can direct the
heated air to various locations of the building being heated.
[0032] FIG. 3 is a side view of a heat exchanger assembly 100
within an outer housing 250. In addition to the heating cabinet 200
that encloses the centrifugal fan 110 and the heat exchanger
tube(s) 102, the outer housing 250 can include an upstream section
302 and a condensing unit 306 comprised of refrigerant compressors,
condenser coils, outdoor fans section, and the like, which can be
implemented to reject the heat extracted by the evaporator coil in
upstream section 302. FIG. 3 provides a view of an example location
of a fan inlet 202 with respect to the heat exchanger tubes 102
within an outer housing 250. Air can be channeled into the fan
inlet 202 from the upstream section 302. The upstream section 302
can be a part of the heating cabinet 200, can be a separate cabinet
within the outer housing 250, or can be separate ductwork that
provides air to the fan inlet 202. The upstream section 302 can
include a filter slot 304 to accept a filter, the filter slot 304
being positioned proximate the cabinet inlet 204.
[0033] The upstream section 302 can also include an evaporator
coil. As will be appreciated, the heating components of a heating
and cooling system can be placed in series after the cooling
components of the system. As will be described in greater detail
with reference to FIGS. 5A-5D, the heat exchanger assembly 100 can
be configured to reduce or eliminate occurrence of condensation
within the tubes 102 that may be caused when the system is in
cooling mode (for example, when cool, air-conditioned air is
flowing across the heat exchanger tube 102 on its way to
corresponding ductwork) and/or when the system is in heating mode
(for example, when the heat exchanger assembly 100 is providing
heat to passing air). When the heating system 50 and the upstream
section 302 are combined into one unit, for example within outer
housing 250, the entire system can be referred to as the HVAC unit
75.
[0034] FIG. 4 is a side perspective view of a heat exchanger
assembly 100 within an outer housing 250. The view shows how the
heating cabinet 200 that houses the centrifugal fan 110 and the
heat exchanger tube(s) 102 can include one or more cabinet outlets
206. The system utilizes a centrifugal fan 110 to pressurize a
plenum space 502, meaning any face of the heating cabinet 200 can
be an outlet, depending on where the outward-flowing ductwork is
placed in relation to the cabinet faces. This is variability of
cabinet outlet 206 placement is discussed in greater detail with
reference to FIGS. 5A-5D.
[0035] FIGS. 5A-5D are side schematic views of heat exchanger
assemblies 100. The different schematics provide various examples
of system geometries and configurations. Referring to FIG. 5A, a
heat exchanger tube 102 can include a first section 104, a second
section 106, and a curved section 108 disposed between the first
section 104 and the second section 106. The first section 104 and
the second section 106 can be substantially straight sections
located at each end of the curved section 108. A radius of
curvature of the curved section 108 can be less than 180.degree.,
as shown in FIG. 5A. In these examples, the first section 104 and
the second section 106 can be positioned in the heating cabinet 200
non-parallel to each other. The less-than-180.degree. curvature can
provide a number of advantages. For one, this construct provides a
wider opening between the ingress portion 112 and egress portion
114 of the heat exchanger tube 102. This large radius bend can,
therefore, facilitate the manufacturability of the heat exchanger
assembly 100, making it possible to slide the heat exchanger tube
102 around the centrifugal fan 110 from the side.
[0036] Another benefit of the large-radius bend in the heat
exchanger tube 102 is the ability to provide a drainage route for
condensate in the heat exchanger tube 102. Condensate may
accumulate on the inside of the heat exchanger tube 102 in a number
of ways. For example, in heating mode, the burner assembly 150
heats combustion gases, and then the heated combustion gases are
routed through the heat exchanger tube 102. At the same time,
ambient-temperature air can flow across the heat exchanger tube
102. This can cause a cooling of the combustion gases within the
heat exchanger tube 102 below the dew point, thereby causing
condensation within the tube. Conversely, in cooling mode, heat
exchanger tube 102 houses ambient-temperate air, yet cool,
air-conditioned air flows across the heat exchanger tube 102 from
the upstream air-conditioning unit. In any event, condensation
within the heat exchanger tube 102 can cause a decrease in
efficiency. To this end, one or more of the first section 104 or
second section 106 can be tilted with respect to horizontal so as
to provide a drainage route for condensate. In FIG. 5A, for
example, the first section 104 has a zero-angle decline with
respect to horizontal, while the second section 106 has a non-zero
angle decline with respect to horizontal. The second section 106
can have a decline angle, wherein a first position 107 of the
second section 106 proximate the curved section 108 is higher with
respect to horizontal than a second portion of the second section
106 proximate the ingress portion 112 of the heat exchanger tube
102. This decline angle can enable drainage out of the second
section 106.
[0037] The schematic in FIG. 5B depicts an alternative
configuration for the heat exchanger assembly 100. The first
section 104 and the second section 106 can be parallel. In these
examples, the radius of curvature of the curved section 108 can be
substantially 180.degree.. In yet another alternative
configuration, as shown in FIG. 5C, first section 104 and the
second section 106 can be parallel, but both sections 104,106 can
be tilted with respect to horizontal. In these examples, both the
first section 104 and the second section 106 can provide a decline
angle (or a non-zero angle with respect to horizontal) to enable
condensate to drain from the heat exchanger tube 102.
[0038] FIG. 5D is a schematic of a heat exchanger assembly 100
without a straight section. The various examples described above
include a straight first section 104 and second section 106.
However, the present systems are not limited to systems with
straight sections on the heat exchanger tube 102. Instead, the heat
exchanger tube 102 can have a circular or substantially circular
geometry when viewed from the side. Stated otherwise, the heat
exchanger tube(s) 102 can be a continuous bend with no distinctive
breaks between the ingress portion 112 and the egress portion 114.
In these examples, a large portion of the outer radius of the
centrifugal fan 110 can be covered by the heat exchanger tube to
provide even distribution of heat to the air flowing radially from
the centrifugal fan 110.
[0039] Referring again to FIG. 5A, a location of the centrifugal
fan 110 with respect to the heat exchanger tube 102 can be altered
so as to adjust the heat transfer efficiency of the system. For
example, a center 111 of the centrifugal fan 110 can positioned at
a first distance 504 from the first section 104 and at a second
distance 506 from the second section 106. The first distance 504
and the second distance 506 can be adjusted based on a number of
factors. The first distance 504 can be greater than the second
distance 506, for example, so as to ensure that the centrifugal fan
110 is located closer to the hotter of the sections (e.g., the
second section 106 can be hotter if located closest to the burner
assembly 150).
[0040] The location of the center 111 of the centrifugal fan 110
with respect to the heat exchanger tube 102 can also be altered
according to the location of the cabinet outlet 206. As described
above, the location of the one or more cabinet outlets 206 can be
changed because the centrifugal fan 110 does not have a single air
outlet. Any face, or panel, of the heating cabinet 200 can,
therefore, be or include a cabinet outlet 206. It is contemplated
that the center 111 of the centrifugal fan 110 can be positioned
such that it is farther away from the cabinet outlet 206, thereby
ensuring a large proportion of the radial airflow exiting the fan
interacts with the heat exchanger tube 102 before exiting the
heating cabinet 200.
[0041] It should also be noted that, as used in the specification
and the appended claims, the singular forms "a," "an," and "the"
include plural references unless the context clearly dictates
otherwise. References to a composition containing "a" constituent
is intended to include other constituents in addition to the one
named.
[0042] Ranges may be expressed herein as from "about" or
"approximately" or "substantially" one particular value and/or to
"about" or "approximately" or "substantially" another particular
value. When such a range is expressed, other exemplary embodiments
include from the one particular value and/or to the other
particular value.
[0043] Herein, the use of terms such as "having," "has,"
"including," or "includes" are open-ended and are intended to have
the same meaning as terms such as "comprising" or "comprises" and
not preclude the presence of other structure, material, or acts.
Similarly, though the use of terms such as "can" or "may" are
intended to be open-ended and to reflect that structure, material,
or acts are not necessary, the failure to use such terms is not
intended to reflect that structure, material, or acts are
essential. To the extent that structure, material, or acts are
presently considered to be essential, they are identified as
such.
[0044] While the present disclosure has been described in
connection with a plurality of exemplary aspects, as illustrated in
the various figures and discussed above, it is understood that
other similar aspects can be used, or modifications and additions
can be made, to the described aspects for performing the same
function of the present disclosure without deviating therefrom. For
example, in various aspects of the disclosure, methods and
compositions were described according to aspects of the presently
disclosed subject matter. However, other equivalent methods or
composition to these described aspects are also contemplated by the
teachings herein. Therefore, the present disclosure should not be
limited to any single aspect, but rather construed in breadth and
scope in accordance with the appended claims.
[0045] The components described hereinafter as making up various
elements of the disclosure are intended to be illustrative and not
restrictive. Many suitable components that would perform the same
or similar functions as the components described herein are
intended to be embraced within the scope of the disclosure. Such
other components not described herein can include, but are not
limited to, for example, similar components that are developed
after development of the presently disclosed subject matter.
Additionally, the components described herein may apply to any
other component within the disclosure. Merely discussing a feature
or component in relation to one embodiment does not preclude the
feature or component from being used or associated with another
embodiment.
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